<template>
  <h3>Hey</h3>
  <button type="button" @click="age++">Update Age</button>
  <greeting :age="age"></greeting>
  <user :age="age" @age-change="age++"></user>
</template>

<script >
 import Greeting from './components/Greeting.vue';
 import User from './components/User.vue';
  export default{
    name:'App',
    components:{
      Greeting,
      User
    },
    data(){
      return{
        age:20
      }
    }
  }
</script>
